Climate change impacts, vulnerability and adaptation in drought severity in the Lower Mekong Basin

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1 Climate change impacts, vulnerability and adaptation in drought severity in the Lower Mekong Basin Mr. Hour Ix Programme Coordinator MRC Drought Management Programme

2 Outline Drought impacts and vulnerability in the - Historical extreme droughts in the - Low flow condition - Socio economic impacts - Types of drought impacts and vulnerability Drought monitoring system and projection Adaptation options Conclusion 2

3 Present statistics indicate that most Mekong Region countries have fairly high amounts of renewable water resources per capita. However, at a closer look, the region (at number locations) faces a series of critical water issues, such as: Water shortages in Thailand; Intensive salinity intrusion in Viet Nam s Mekong delta; Floods and drought in most parts of the ; Water quality, land-subsidence, and morphological changes in Delta areas; and Intensification of sectoral competition within and among the Mekong countries (MRC, 2010a). 3

4 The Mekong River has an average annual discharge of 13,700 m 3 /s, a peak wet season average discharge of 52,400 m 3 /s, causing widespread flooding, and a minimum discharge of 1,600 m 3 /s (approximately 30 times less than the peak wet season discharge) during dry season, when water demand for food production is higher (ADB and SEI, 2002, and MRC, 2003). Figure 1: Mekong at Kratie the two most extreme annual hydrographs observed over the 86 years since

5 Historical extreme drought in the Drought events in the region have increased in frequency and severity during the past decades. Regionally, the timing of the onset and end of the south west monsoon is highly predictable, historically having a very low variance from year to year. As recent experience has shown, any significant deviation from these dates can have substantial economic consequences. Twelve significant and four extreme drought episodes have occurred since 1924, making them an integral part of the hydrological landscape of the. The most extreme events in 1955, 1992, 1997, 1998, and

6 Hydrological drought in the Figure 2: Scatter plots of the joint distribution of the annual maximum discharge (cumecs) and the volume of the annual maximum hydrograph (km3) Vientiane/Nong Khai ( ) and at Kratie ( ). Source: Adamson and Bird,

7 Hydrological drought in the Figure 3: Hydrograph at Mekong Vientiane and Kratie. Water level, [m] HYDROGRAPH AT MEKONG - KRATIE Jun Jul Aug Sep Oct Nov Dec 100 Fluctuation Preci-2014 Average Alarm Level Flood Stage

8 Socio economic impacts Table 1 Typical examples of impact of drought and floods in Cambodia. IDD = International Disaster Database; ADB = Asian Development Bank Disaster Date Affected Damage (person) (1000s US$) Source Flood June ,470, IDD Flood July ,300,000 1,500 IDD Flood August ,448, ,000 IDD Flood August ,669,182 15,000 IDD Drought 2003 to 2,000,000 Unknown ADB 2005 Drought June ,000, ,000 IDD Table 2 Typical examples of impact of drought and floods in Lao PDR ( ). WFP = World Food Programme Disaster No. Events Affected (person) Source Drought 5 4,250,000 WFP Flood 16 3,244,150 WFP 8

9 Socio economic impacts Table 3 Typical examples of impact of drought and floods in Thailand. ADB = Asian Development Bank; GAR = Global Assessment Report Disaster Date Affected Impact Source Drought 2003 to 650,000 ha Increased farm production cost ADB % Drought ,444,010 Decreased agricultural product GAR persons Flood ,822 Unknown GAR persons Drought 2010 Unknown Lost 75% of Cassava production & increased price 60% Bangkok Post Table 4: Typical examples of impact of drought and floods in Viet Nam. (ADB = Asian Development Bank) Disaster Date Affected Impact Source Drought 2003 to Unknown $ 60 million (Cuu long delta) ADB 2005 Drought (North central) June ,000 households, 250,000 ha Not enough clean water; crops dried up; high tem. Viet Nam Net 9

10 Socio economic impacts - Cambodia 4 10

11 Socio economic impacts - Cambodia Figure 5: Total Crop Area Damaged by Drought Figure 6: Dry Season Rice Cultivated Area,

12 Drought impacts and vulnerability in the Socio economic impacts - Laos 2nd Mekong Climate Change Forum 12

13 Drought impacts and vulnerability in the Socio economic impacts - Thailand 2nd Mekong Climate Change Forum 13

14 Socio economic impacts Vietnam 14

15 Drought Risk Map of the Drought Risk Model using 6 weighing factors: - Meteorology - Irrigation - Ground water rate - Surface water - Soil drainage - Land use 15

16 Types of drought impacts and vulnerability Economic Annual and perennial crop losses and damage to crop quality Reduced productivity of cropland (wind erosion, etc.) Insect infestation Crop disease Loss of farmers through bankruptcy Unemployment from drought-related production declines Increase in food prices Increased importation of food (higher costs) Reduction and degradation of sh and wildlife habitat Lack of feed and drinking water 16

17 Types of drought impacts and vulnerability Environment Damage to plant species Forest res Estuarine impacts (e.g., changes in salinity levels) Loss of biodiversity Soil erosion and water quality degradation 17

18 Types of drought impacts and vulnerability Social Mental and physical stress (e.g., anxiety, depression, loss of security, domestic violence) Reductions in nutrition (e.g., high-cost-food limitations, stress-related dietary de ciencies) Inequity in the distribution of drought relief Increased poverty in general Population migrations (e.g., rural to urban areas, migrants into neighboring Country to seek for work) 18

19 Drought monitoring system and projection Drought Indicator Indices being studied by DMP NDVI: 250m of 8 days composite with signed 16 bite data with atmostphere correction. The products will be 8 days and monthly basis TDVI/SMI: Temperature Vegetation Index, is using 1 km resolution data with 8 days composite. The products will be 8 days and monthly basis GSmap: Global Satellite Mapping of Precipitation, is using 1km resolution data with daily and monthly products KBDI: is using 1km resolution data with daily and monthly products SPI: is using observed data of MRC with triangular method to cover the whole by GSmaP 19

20 Adaptation options Water diversion to dried crop land by generators Changing crop varieties Micro finance/loans from bank Irrigation system rehabilitation and extension through new development projects Building water storages Migration out for additional incomes Building dykes to prevent sea water from intruding to rivers Pumping ground water Reforestation 20

21 Conclusion Ground water exploration and use should be encouraged and applied more efficiently for agricultural irrigation specifically in Cambodia and Lao PDR Drought projection is still at the study stage where there is no accurate model available yet Downscaling climate change projection on potential drought risks and vulnerability is the most significant task to be carried out in order to project long-term scenarios on climate change impacts in drought severity for a better adaptation option and planning Adaptation planning to mitigate drought and climate change impacts needs to consider trans-boundary inter-connection especially hydrological factor in both natural and man-made activities specifically hydro power operations in the main rivers and tributaries. 21

22 Thank you